Packing machines are known to feature reel feeding devices for successively transferring reels from a store to an unwinding unit by means of a transfer device having an arm fitted with gripping members for picking up and retaining a reel. To transfer the reels, the arm is moved cyclically from a pickup station at the store to a supply station at the unwinding unit.
In particular, U.S. Pat. No. 4,441,662 describes a device for feeding reels from a store, along which the reels are fed parallel to their respective axes and in a supply direction to an unwinding unit. The device features a guide extending in a conveying direction crosswise to the supply direction of the store, and which supports a slide traveling along the guide in the conveying direction. The slide supports an arm, which rotates with respect to the slide about an axis of rotation parallel to the conveying direction, and is fitted with gripping members for gripping a reel.
The cyclic movement, between the pickup and supply stations, of the arm fitted with the gripping members comprises longitudinal movements in the conveying direction, and transverse movements in a direction crosswise to the conveying direction. The transverse movements are performed by rotating the arm as described, while the longitudinal movements are performed by the slide moving as described along the guide.
The feeding device described in the above patent is mechanically complex, by a moving part--the slide--supporting a further part--the arm--in turn movable with respect to the slide, as well as the respective actuating means. And the situation is further complicated by the arm also supporting moving parts--the gripping members--and the respective actuating means.